DIMINUTION OF BIOLOGICAL REACTIVITY OF ETHANOL BY CHANGING THE SOLUTION STRUCTURE BY WEAK ULTRASONICATION

The weak ultrasonication (40 kHz, 12 mW, 1 week) of ethanol solutions was found to reduce stimulation of the senses of smell and taste by th e ethanol on the basis of blind tests with an aqueous ethanol solution (33.0% w/v) and an immature distilled spirit (25.0% v/v). Experiments on mice also demonstrated that a treated aqueous ethanol solution had a weaker depressant effect on the central nervous system, as evaluate d by the relative frequency with which mice regained the righting refl ex at a dose of either 4.0 or 4.5 g/kg (p < 0.05 or p < 0.01, respecti vely) and by the reduction in rectal temperature at a dose of 5.0 g/kg (p < 0.05) soon after ethanol administration. Analyses of both the et hanol concentration by head-space gas chromatography and the free radi cals by electron spin resonance spectrometer failed to reveal any chem ical changes in aqueous ethanol solutions subjected to weak ultrasonic ation. However, measurement of the spin-lattice relaxation time (T1) o f the H-2 of water molecules by H-2-NMR showed that the treatment slig htly accelerated the thermal motion of water molecules in the solution s. Treated solutions were also found to have a slightly higher density than untreated ones. These physical data demonstrate that weak ultras onication induces a structural change, such as a more compact and homo geneous structure by changing the microdynamic behavior of the solutio n. These biological and physical studies suggest that only a slight st ructural change in an ethanol solution induces a marked change in the biological reactivity of ethanol without any chemical modification of the solution itself.